Difference Between Transverse and Longitudinal Waves

Transverse waves and longitudinal waves are the two main types of wave propagation. These two concepts are extremely important and are particularly useful in explaining many phenomena related to wave mechanics. In this article, we are going to compare transverse wave with longitudinal wave, and discuss their definitions, similarities and finally their differences.

What is Transverse Wave?

In waves and vibrations, the concept of transverse waves is a corner stone. Transverse wave is one of the two basic forms of waves. To understand a transverse wave, an essential understanding of wave mechanics is required. A wave is a method of transferring energy. As the wave propagates through the space, energy it carries is also propagated. This energy causes the particles on the way, to oscillate. In other words, the energy is propagated through the oscillation of particles. In transverse wave, particles oscillate perpendicularly to the direction of wave motion. It must be noted that particles do not move in the direction of propagation even slightly. For a sinusoidal wave, the particles oscillate in a simple harmonic motion. For any wave, the largest displacement of the particle from the equilibrium point is equal to the amplitude of the wave, and it is proportional to the energy carried by the wave. Waves such as light waves and other electromagnetic waves are transverse. Normal light waves have oscillations in every direction perpendicular to the propagation. A plane-polarized ray would have oscillations in only one direction.

What is Longitudinal Wave?

Longitudinal wave is the other main type of waves, which are present in nature. The same principles of wave dynamics apply to longitudinal waves. In a longitudinal wave, the oscillations of particles are parallel to the direction of propagation. This does not mean the particles are moving with the wave. The particles only oscillate about a fixed equilibrium point in space. Since the oscillations are parallel to the movement, a pressure difference is caused. A longitudinal wave also can be considered as a pressure wave since the energy is transferred through pressure. It must be noted that unlike the transverse waves, the longitudinal waves only have one direction of oscillation. The maximum displacement from the equilibrium point is equal to the amplitude of the wave, and it is proportional to the energy of the wave. Sound waves are the best example of longitudinal waves. The pressure difference between the inside of our ear and outside varies due to pressure variation created by the sound wave. This causes the diaphragm of the ear to oscillate which is then detected by the sound sensing neurons.

What is the difference between longitudinal waves and transverse waves?

• Transverse waves create oscillations that are normal to the direction of propagation, but the longitudinal waves create oscillations that are parallel to the propagation of the wave.

• Transverse waves have oscillations in many different directions, but longitudinal waves have oscillations in only one direction.

• Natural ocean waves are created by a superposition of longitudinal and transverse waves.